The present invention relates to batteries, more particularly to methods and apparatuses for testing thermal characteristics of batteries such as Lithium-ion batteries.
Lithium-ion batteries have become commonplace in many everyday items such as laptops, cell phones, and other portable electronics. Lithium-ion batteries are also used in more demanding environments, such as electric vehicles and military applications. It is known that the performance of Lithium-ion batteries is sensitive to ambient temperature. In addition to the risk of battery failure from overheating, it is desirable for the battery system to maintain uniformity in temperature across the individual cells within the system.
Lithium-ion (Li-ion) batteries are known for risk of fire when operated at higher temperatures, e.g., temperatures above approximately 60° C. Catastrophic failure of Lithium-ion batteries has been known to occur due to “thermal runaway.” If the internal temperature of a Lithium-ion battery exceeds an onset temperature, this may result in thermal runaway whereby chemical reaction rates increase uncontrollably, possibly leading to fire and/or explosion. As a historical example, failure of Lithium-ion batteries onboard the Boeing 787 Dreamliner was publicized in 2013. Many product recalls have involved Lithium-ion batteries.
There is growing interest in finding thermal management solutions for alleviating safety concerns associated with high temperatures of operation of Lithium-ion batteries. Companies, universities, and government labs are evaluating various thermal management systems for keeping Lithium-ion batteries cool during operation to avoid failure. In seeking solutions for maintaining cooler operation temperatures of Lithium-ion batteries, investigators wish to minimize risks of damage to property and injury to themselves while they conduct their testing. Current practice of heat transfer testing of Lithium-ion batteries involves complicated and expensive safety procedures.